Learning About How Alcohol Harms the Body

Scientists are finding that even moderate drinking may be more harmful than we thought—and certain groups are more at risk.

Humans have been drinking alcohol for thousands of years—it’s part of our culture to raise a toast in celebration with friends or nurse a glass of wine or beer at the end of a long day.
But what is all that booze doing to our bodies? Scientists are increasingly finding that even moderate drinking may be more harmful than we thought. 
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Alcohol is a group-1 carcinogen, linked to cancers of the mouth, pharynx, larynx, esophagus, liver, colorectum, and breast. In 2023, the World Health Organization declared there is no safe amount of alcohol to consume—adding that there’s no evidence that the potential cardiovascular benefits of a glass of red wine outweigh its cancer risks.

Certain people are at greater risk too. Here’s just some of what National Geographic’s reporters have learned in recent years about how alcohol affects your body—and what you can do about it.

1. The effects of alcohol are way worse for women 

“Even when consuming the same amount of alcohol as men, women are more susceptible to its negative effects,” wrote Meryl Davids Landau in an August 2023 story. Alcohol-related deaths are climbing in women, and lifetime risk of breast cancer rises as much as 9 percent with just one daily drink. Booze can also affect fertility and menopause.

Experts told Landau that this is partly because women have more fatty tissue and less body water than men of similar weight, which leads to higher blood-alcohol concentration. “Women also have fewer enzymes that metabolize alcohol,” she wrote. “And their hormonal fluctuations are thought to play a role in how quickly alcohol breaks down.”

Women also may not realize how much they’re drinking. What’s the best rule of thumb? Read the full story here.

2. It really does get harder to drink as you age

It’s not just women whose bodies have a harder time dealing with alcohol—as we get older, everyone becomes more vulnerable.

Like women, all of our bodies have less body water as we age. “If you drink the same amount at 80 as you did at 30, your blood alcohol level will be much higher,” said Alison Moore, director of the Stein Institute for Research on Aging and the UC San Diego Center for Healthy Aging, in Stacey Colino’s July 2024 story on aging and alcohol intolerance.

Additionally, enzymes that help our bodies metabolize alcohol diminish with age. And the aging brain is also more vulnerable to the effects of alcohol, which can affect coordination and balance—resulting in a higher risk of falls and impaired reaction time.

What are the consequences of these changes to your body? Read the full story here.

3. Those changes may be more sudden than you think

Have you ever woken up with a hangover and suddenly really felt your age? That’s for good reason. Researchers have found that our bodies actually age in two “bursts” at 44 and 60, as Daryl Austin reported in September 2024. Those molecular changes can account for some of the sudden visible changes to our bodies such as sagging skin and wrinkles.

It can also account for our worsening hangovers. At age 44, some of the molecular changes that scientists observed occurred in cells affecting our ability to metabolize alcohol.

Is there anything you can do to mitigate these effects? Read the full story here.

4. Drinking before bedtime is particularly bad for you
                
It’s no surprise that a night of hard drinking can mess with your sleep. But scientists are discovering that even just a nightcap can cause problems, as Tara Haelle reported in a June 2023 story.

"Sleep is designed to give you sort of a cardiac holiday—your heart rate drops, your blood pressure drops, etc.," said Ian Colrain, president and CEO of MRI Global, a research institute based in Kansas City, Missouri. But alcohol elevates your heart rate—and Colrain’s research has found that even a little bit of alcohol can keep your heart rate elevated for four hours of sleep.

Drinking before bedtime can also fragment your REM sleep, and boost your risk for sleep apnea and alcohol addiction. Read the full story here.

5. Drinking on a plane might be even worse

It might be even worse to have a nightcap when you’re on a long-haul flight. As Leah Worthington reported in July 2024, new research has found that alcohol “compounds the effects of high altitude on people’s bodies, putting an extra burden on the cardiovascular system, reducing blood oxygen levels, compounding dehydration, and impairing sleep quality.”

Although young and healthy people may be able to tolerate some amount of hypoxemia, or reduced oxygen in the lungs and bloodstream, there can be serious consequences for older people or those with heart or lung disease. Read the full story here. 

6. This is why you wake up anxious after drinking

Even young and healthy people may not escape one effect that alcohol has on the body: hangxiety. Yes, if you’ve ever woken up after an evening of drinking feeling nervous or uneasy, science suggests that the booze you consumed really is the culprit. 

As Meryl Davids Landau reported in March 2024, alcohol interferes with certain neurotransmitters in the body that keep your anxiety in check.

​Even when the alcohol is out of your system, its toxic byproduct acetaldehyde can continue to wreak havoc. “Throughout the day, as the acetaldehyde is excreted, your body is recovering from having been poisoned,” said Stephen Holt, director of the Yale-New Haven Hospital’s addiction recovery clinic. This can cause symptoms like nausea and fatigue—which in turn can make you feel more anxious.

Do hangover cures help? Read the full story here.

7. The effects of alcohol can be reversed—within weeks

Acetaldehyde also builds up in the cells of your liver. How long they do so can determine how much damage your liver sustains. But the good news is that these effects can be reversed in just weeks—suggesting that Dry January is more than just a buzzy health trend, as Rachel Fairbanks reported in October 2023.

“The liver has an enormous regenerative capacity,” says Paul Thomes, a researcher at Auburn University, whose work focuses on the mechanism of alcohol-induced organ damage. Of the four stages of alcohol-related liver disease, the first three can be reversed simply by not drinking.

There are also other benefits from abstaining from alcohol for a month. Read the full story here.

8. Want to take a break? These tips could help

As we learn more about the health harms of alcohol, new alternatives are emerging. Mocktails and other nonalcoholic are gaining popularity—and even tasting better thanks to new developments in food science. As we previously reported, studies show that these drinks really do help people cut back on booze and mitigate its harmful health effects.

Sober travel is also on the rise, as we reported in April 2023, making it possible for everyone to explore new cultures. (Even those cultures where a glass of wine or beer or a shot of something bitter is typically considered part of the journey.) Many tour companies are even offering booze-free excursions.

“People are just so happy to connect with others who have gone through a similar life experience,” Lauren Burnison, founder of We Love Lucid, a European sober tour company, told us. “There’s such an upbeat vibe, and it’s great to wake up without a hangover.”